When changing locations in Network via System Preferences and the DHCP service does not provide directly a new IP address, one does not need to restart the computer. A network reset suffices. This can be given via the terminal:

Another "non-cli" approach is to make a new Network Location in the Network System Preference and then in the "Show" port configuration popdown, deactivate all of the interface checkboxes. When you want to reset networking (or need to shutdown all networking except lo0), just select this "No Network" Location, reselect the Location you want, and you're done.